1. Field of the Invention
The present invention relates to lancets of the type used to pierce the skin for obtaining a minute quantity of blood for analysis. More particularly, the present invention relates to a lancet assembly having an improved safety cap adapted for ease of removal and for secure closure and shielding of the contaminated lancet needle tip after use.
2. Description of the background art.
Lancets are often used to puncture the skin so as to facilitate the sampling of human blood for testing and/or analysis. For example, lancets are frequently used to obtain small amounts of blood by puncturing an appropriate area, such as the patient's fingertip. Blood samples obtained using lancets may be blotted or smeared onto various test strips or reagent pads in connection with various testing methods. For example, the blood of persons suffering from diabetes may be regularly tested using lancets to test glucose content. In addition, a wide variety of other tests may be employed using only small amounts of blood obtainable from lancet punctures.
Puncture wounds are commonly produced using disposable lancets. Such devices include a lancet body having a sharp pointed needle member that may be manipulated to produce a quick, and relatively painless, puncture of the patient's skin in order to produce at least a droplet of blood. An example of such a lancet is found in U.S. Pat. No. 3,358,689, issued to Higgins, wherein a lancet needle is encased in an elongated plastic body with the needle tip embedded in a removable protective cap integrally molded with the plastic body to form a single integral unit prior to use.
Lancets are typically sterilized during production, and maintained in a sterile condition before use to prevent contamination of the lancet needle. In order to avoid contamination, lancets of the background art are manufactured with integral protective caps in order to prevent exposure and/or contamination of the lancet needle during post-manufacturing handling, shipping, and storage.
Lancets are commonly used in clinical and hospital settings by medical professionals, and are also used by individuals and patients outside of medical facilities, such as at home. Lancets may be used to puncture the patient's skin either alone by manual penetration, or in conjunction with a spring-loaded device developed to drive the lancet needle into the user's skin rapidly. Furthermore, due to concerns about communicable diseases transmitted through body fluids such as blood, the lancet must be carefully gripped to avoid contact with the sharp end of a lancet that has been contaminated with blood. Accordingly, after using the assembly, sufficient care must be taken by the user to avoid being punctured by a used lancet assembly, and the lancet assembly must be carefully handled until it is properly disposed.
As a result of these concerns, advances have been made in recent years to increase safety in handling such used devices. U.S. Pat. No. 5,385,571, issued to Moriata, discloses a lancet body having a needle end protruding from a lancet end, and a needle protector for protecting the needle. The needle protector comprises a cap or hood configured to tightly fit on the lancet end from which the needle end protrudes to insulate the needle end after use. The cap is integrally molded with the lancet body so as to be bonded to the top surface of the lancet body by a narrow neck. In order to use the lancet, the user must manually grasp and remove the cap, such as by twisting. Such is also the case with the lancet disclosed in U.S. Pat. No. 3,358,689, and most other lancets currently in use.
While the background art reveals a number of improvements directed to lancet designs, there exists a need for further improvements to facilitate ease of use. Specifically, it has been found that people often experience difficulty in removing the protective cap, due largely to the relatively small size of the lancet cap and the fact that lancet caps known in the art are not shaped to facilitate easy grasping and removal. Removal of the protective cap is particularly troublesome for the young, the elderly, and those suffering from injury or disease effecting use of the hands.
Accordingly, there exists a need for an improved lancet design that overcomes the disadvantages associated with the use of lancets of the background art.